3rd grade
posted by Skyshun .
I am less than 100.
The sum of my digits is 4.
Half of me is an odd number.

If you multiply me by 2, i become a number greater than 20 and less than 40.
If you multiply me by 6, I end in 8.
If you multiply me by 4, I end in 2. 
If less that 100, there are only two numerals. What two numerals add to 4 (1 + 3 or 2 + 2)? Take your pick to fit the remaining information.
If multiplied by to to get > 20 and < 40, then dividing those two numbers by 2 would give you the possible range of the actual number (1119). Try numbers in that range to find what fits the other two requirements.
> = greater than
< = less than 
i am less than 100 the sum of my digits is 4 half of me is an odd number who am i